LIC AAO Model Paper 6

$7^1$ = 7 . $7^2$ = 49 ; $7^3$ = 343 ;
$$7^4 = 2401 ; $7^5$ = 16807
Hence, unit’s digit repeats after index 4 .
Remainder when 1987 is divided by 4 = 3
Unit’s digit = 3
Hence, remainder on division by 5 = 3